Sliding door construction utilizing an inflatable seal

ABSTRACT

A sliding door construction for a railway car incorporating an inflatable seal to seal the space between the door and the frame bordering the doorway in the car. The door is mounted to slide longitudinally along the side wall of the car to open and close the doorway. To guide the door in sliding movement the lower end of the door carries a series of rollers having V-shaped peripheral grooves that ride on a V-shaped rail, while the upper end of the door is provided with a series of anti-friction elements that ride against the door frame. As the door is spaced laterally outward so that it can slide freely with respect to the car, an inflatable seal is associated with the peripheral edge of the door and when inflated serves to seal the space between the door and the frame. The mechanism for inflating and deflating the seal is associated with the locking device for the door and is arranged to supply hydraulic fluid to the seal to inflate the same when the locking device is engaged and to withdraw the fluid to deflate the seal when the locking mechanism is disengaged.

United States Patent [191 Herr [451 July 17,1973

[ SLIDING DOOR CONSTRUCTION UTILIZING AN INFLATABLE SEAL [76] Inventor: Theodore Z. Herr, 672 Hyacinth PL,

Highland Park, Ill. 60035 22 Filed: Aug. 18,1971

21 Appl. No.: 172,811

[52] US. Cl. 49/449, 49/477 [51] Int. Cl. E05d 13/04 [58] Field of Search 49/316, 319, 303,

[56] References Cited UNITED STATES PATENTS 3,302,333 2/1967 Ganzinotti et al. 49/477 X 3,449,864 6/1969 Frost-Dame et al. 49/477 FOREIGN PATENTS OR APPLICATIONS 547,072 8/1942 Great Britain .7 49/477 Primary Examiner-Kenneth Downey Attorney-Andrus, Sceales, Starke & Sawall [57] ABSTRACT A sliding door construction for a railway car incorporating an inflatable seal to seal the space between the door and the frame bordering the doorway in the car. The door is mounted to slide longitudinally along the side wall of the car to open and close the doorway. To guide the door in sliding movement the lower end of the door carries a series of rollers having V-shaped peripheral grooves that ride on a V-shaped rail, while the upper end of the door is provided with a series of antifriction elements that ride against the door frame. As the door is spaced laterally outward so that it can slide freely with respect to the car, an inflatable seal is associated with the peripheral edge of the door and when inflated serves to seal the space between the door and the frame. The mechanism for inflating and deflating the seal is associated with the locking device for the door and is arranged to supply hydraulic fluid to the seal to inflate the same when the locking device is engaged and to withdraw the fluid to deflate the seal when the locking mechanism is disengaged.

15 Claims, 14 Drawing Figures PATENTEDJUH H975 3.745.707

SHEH 3 @F 3 7 INVENTOR. THEODORE z. HERR BY A Attorneys PA'I'ENTEDJULI'HBIS 3 745,707

SHEH' 3 BF 3 R R a% O Z N WE NR 1 O D O E H T FIG. 4

Attorneys w-lll mrlv FIG l2 7% 74 7i i 75 77 2? a 111 1 I I I II PATENTEB JUL 1 1 I973 INVENTOR. THEODORE Z. HERR BY q Attorneys SLIDING DOOR CONSTRUCTION UTILIZING AN INFLATABLE SEAL BACKGROUND OF THE INVENTION Sliding flush doors are commonly used to enclose the openings in a railway car and are mounted on tracks to slide longitudinally along the wall of the car between an open and a closed position. Conventional sliding doors for railway cars have been the. subject of much dissatisfaction among users in that they are extremely difficult to manually open and close. Due to weather proofing requirements the conventional sliding door is designed with a clearance between the door and the side wall of the car of only 1/16 inch. Because of imperfections in manufacture or damage to either the door or the frame members, the door will invaliably rub against the frame. Moreover, the upper edge of the door normally bears in a steel-to steel relation with guide members on the door frame and this also provides substantial frictional resistance to opening and closing of the door. The door nonnally rides on a flat track and is laterally guided by metal flanges that bear against the track, resulting in additional frictional resistance. This situation has given rise to the use of specially designed door openers or wheel and gear arrangements connected to the side of the car for the purpose of aiding in opening and closing the sliding door. In other instances operators have used a fork lift truck to move the doors, and as the strength of the door edges is limited, the use of the lift truck causes permanent deformation of the edge of the door and contributes to the increased difficulty in sliding.

Some sliding doors are adapted to rest on nonrotatable bases to prevent accidental rolling when in the open position. Doors of this type require that a mechanism be operated to raise the door physically from the base when it is to be rolled to the closed position. This arrangement is unsatisfactory in that it is difficult to operate the mechanism from dock level.

SUMMARY OF THE INVENTION The invention is directed to a sliding door for a railway car which will roll freely between the open and closed position and is capable of being operated by one man either at ground level or dock level.

The sliding door of the invention includes a generally flat plate which is reinforced along its edges by stiffeners. Bordering the opening in the car is a frame and when the door is in the closed position, flanges of the door stiffener are located within pockets or recesses on the frame so that the door is fully supported against internal loading. Moreover, the interlocking flanges of the door and the frame provide a circuitous route for the entry of air and foreign material.

To guide the door in movement between and open and closed position, a series of rollers are journalled on the lower edge of the door and each roller is provided with a peripheral groove which rides on a generally V- shaped rail. The engagement of the rollergroove with the V-shaped rail prevents lateral displacement of the lower portion of the door with respect to the car. In addition to the rollers, the? upper edge of the door carries a series of anti-frictional elements, made of nylon or polytetrafluorethylene (Teflon), which ride against a guide member on the door frame.

The door of the invention is spaced outwardly from the side of the car approximately V4 inch, which is a greater distance than normal so that the door can slide freely without interference from the frame members. Since the clearance between the door and the car wall is increased, weather tightness is achieved through use of an inflatable seal which is attached to the peripheral edge of the door. When the door is in the open position the seal is delfated so that the seal lies within the inner surface of the door so that there is no interference with sliding movement. When the door is closed and locked, the seal is automatically inflated to thereby provide a continuous weather-tight seal around all four edges of the door.

To inflate and deflate the seal, a unique mechanism is utilized which is contained within the confines of the door and does not require external power, but instead is operated manually as a consequence of manual locking and unlocking of the door. More specifically, the inflating mechanism includes three diaphragm cylinders or pumps which are mounted within the door and are connected through a hydraulic line to the seal. The diaphragm cylinder of largest volume is operably connected to the locking lever for the door, while the second or pressurizing cylinder is operably connected to an auxilliary lever and the third cylinder is utilized as an expansion chamber.

After the door is closed, the locking lever on the outside of the door is moved to the locking position which locks the door in the closed position. Moving the locking lever to the locking position simultaneously operates the diaphragm of the larger or main cylinder to supply hydraulic fluid to the inflatable seal to substantially fill the seal with the fluid. After moving the locking lever to the locking position, the auxiliary lever is moved to the closed position which operates the pres surizing cylinder to pressurize the fluid within the seal to fully inflate the same and. provide a weather-type seal to the door frame. The locking lever and auxiliary lever are arranged so that the locking lever must be moved to the closed or locking position first, followed by movement of the auxiliary lever, thereby insuring that the main diaphragm cylinder will be initially operated followed by the pressurizing operation.

When opening the door, the auxiliary lever is initially moved to the open position thereby releasing the pressure on the fluid within the seal. When the locking lever is then :moved to the unlocked position, the fluid is withdrawn from the seal and returned to the main cylinder, thereby enabling the seal to deflate to a position out of contact with the door frame so that the door can then slide without interference with the side of the car.

The sliding door construction of the invention has substantial advantages over prior art structures. As the clearance between the door and the car has been increased, there will be no interference to sliding movement of the door even if the door or the car wall may be slightly bent or deformed. With the use of the inflatable seal, a positive and complete seal is provided around the periphery of the door and the sealing characteristics are retained even though the frame or door may be slightly bent or deformed.

The inflatable seal combined with the sliding door provides a unique combination because both the seal and the mechanism for inflating and deflating the seal are permanently mounted within the door and no auxiliary power is required. When the seal is deflated, the seal is confined within the inner surface of the door, thereby permitting the door to slide freely. When the door is in the locked position the seal is automatically inflated effecting a continuous weather-tight seal around all four edges of the door opening.

The hydraulic system which is utilized for inflating and deflating the seal is permanently sealed within the door against leakage. The use of the diaphragm pumps eliminates the need for expensive and finely machined cylinders, packings, etc., which are custol'narily used in a hydraulic system. This not only decreases the initial cost but also reduces maintenance for the hydraulic system and is virtually leakproof. Moreover, no part of the hydraulic system is exposed so that it will not be subject to shock or damage.

The use of the diaphragem type pump also has the advantage that it provides a compact unit which can be readily located within the width of the door which has a maximum dimension of 2 15/32 inches.

The door locking mechanism is also unique in that in addition to providing an over-center toggle locking arrangement the latch is restrained in downward movement when the door is unlocked so that if the door slides to its closed position, it will automatically engage a locking pin and thus be restrained from opening again even though the door is not fully closed.

The invention includes a mechanical interlock between the locking lever and the auxiliary lever and provides a built in operating sequence, thereby making detailed instructions for opening and closing the door unnecessary.

Other objects and advantages will appear in the course of the following description.

The drawings illustrate the best mode presently contemplated of carrying out the invention.

In the drawings:

FIG. 1 is a side elevation of a railway car incorporating the sliding door of the invention;

FIG. 2 is avertical section taken along line 2-2 of FIG. 1;

FIG. 3 is a horizontal section taken along line 3-3 of FIG. 1;

FIG. 4 is an enlarged side elvation showing the door locking mechanisn;

FIG. 5 is a section taken along line 5-5 of FIG. 4;

FIG. 6 is a section taken along line 6-6 of FIG. 4;

FIG. 7 is a section taken along line 7-7 of FIG. 4;

FIG. 8 is a section taken along line 8-8 of FIG. 4;

FIG. 9 is a section taken along line 9-9 of FIG. 4;

FIG. 10 is a section taken along line 10-10 of FIG.

FIG. 11 is a section taken along line 11-11 of FIG. 4 and showing the interlock between the levers;

FIG. 12 is a section taken along line 12-12 of FIG.

FIG. 13 is a section taken along line 13-13 of FIG. 4; and

FIG. 14 is an enlarged cross section of the seal.

In the drawings, FIG. 1 shows a railway car 1 having an opening or doorway 2 adapted to be closed by a sliding flush door 3 of the invention.

members opening 2 in the car 1 is bordered by a frame which includes a pair of vertical side member 44 and 5, and an upper Z-shaped member 6 which is secured to the side wall of the car above the opening 2. In addition, the frame includes an upper horizontal channel 8 that is secured to the lower portion of the vertical flange of the angle 7, as well as to the upper ends of the side members 4 and 5, and is located beneath the horizontal web of member 6. The lower edge of the opening 2 in the car 1 is bordered by an angle shaped sill 9.

The sliding door 3 is formed of flat plates 10, reinforced by a series of horizontal stifi'eners l 1 that are attached to the outer surface of plate 10. The ends of the stiffeners 11 are attached to side members 12 and 13 which extend along the side edges of the plate 10. In addition, an upper reinforcing member 14 is secured to the upper edge of the plate 10, as shown in FIG. 2, and extends between the side members 12 and 13, and a lower reinforcing member 15 is welded to the lower edge of plate 10 and also extends between the side members 12 and 13.

As best illustrated in FIG. 3, the vertical frame member 5 bordering the opening 2 has a generally S-shaped section, including a flange 16 which is attached to the side of the car 1. The outer portion of the frame member 5 defines a recess or pocket 17 to receive the end 18 of side member 12 of the door. The vertical edge of the door side member 12 is formed with an inwardly extending flange 19 which bears against the surface 20 of the frame member 5 to provide a partial seal between the door and the frame member. The edge 21 of frame member 5 diverges outwardly so that the end 18 can be moved into the pocket 17 without interference.

As illustrated in FIG. 3, the side member 12 of the door is provided with a surface 22 which is offset inwardly from the surface 18 and is attached to the outer face of plate 10.

The side member 4 is U-shaped in cross section and is provided with a flange 23 which is attached to the outer surface of the car 1. V

In addition to the flange 23, side member 4 is formed with a shorter flange 24 which is adapted to be received within a pocket or recess 25 in the door side member 13 when the door is in the closed position. As shown in FIG. 3, the side member 13 terminates in a diverging flange 26 that is located inwardly of the flange 24 of side member 4 when the door is in the closed position. The diverging contour of the flange 26 enables the flange 24 to be received within the pocket 25 without interference. The interlocking nature of the flange 24 and the pocket 25 provides a circuitous route for the entry of air or foreign material through the space between the door and the door frame.

The door side member 13 is provided with a flat inwardly offset surface 27 which is attached to the outer surface of the plate 10.

As shown in FIG. 2, upper frame member 6 is provided with an upper flange 28 which is connected to the vertical flange of the angle 7. Flange 28 terminates in a web 29 which extends outwardly and upwardly at a shallow angle from car 1, and the web is formed integrally with a lower vertical flange 30 which serves as a guide rail or track for guiding movement of the upper edge of the door 3. The angle of the web fonns a gutter to prevent water from the car roof from draining into the door opening.

The upper member 14 of the sliding door 3 is provided with a central, inwardly offset surface 31 which is attached to the plate 10, and the upper edge of the member 14 terminates in a vertical flange 32 which is located inwardly of the flange 30 of the frame member A pair of straps 33 are secured to the member 14 and the upper end of each strap is bent inwardly to define a flange 34 that is spaced above the web 29 of frame member 6 to prevent displacement of the door if it is disengaged from the lower track.

To reduce the sliding door friction between the upper edge of the door and the frame, pads 35 and 36, forms of an anti-friction material such as nylon or Teflon (polytetrafluoroethylene), are mounted on the straps 33 and flanges 32 respectively. As the door moves along the side of the car 1, the pads 35 and 36 ride against the flange 30 on frame member 6 to reduce the frictional resistance.

The lower reinforcement for door 3 is formed with a U-shaped section 37 that is bordered by a pair of inwardly offset surfaces 38 and 39, both of which are attached to the lower portion of plate 10. As shown in FIG. 2, a pair of guide rollers 40 are mounted for rotation on lower reinforcement 15 and are adapted to ride on a rail 41 secured to the car 1. As best illustrated in FIG. 2, each of the rollers 40 is joumalled on a shaft 42, and the inner end of the shaft is secured within an opening in the vertical surface 43 of member 15, while the outer end of each shaft is secured within an opening in plate 44 which extends downwardly from the section 37 and is located in spaced parallel relation to the surface 43.

As shown in FIG. 2, the periphery of roller 40 is provided with a V-shaped notch 45 which is adapted to ride on the upper V-shaped ridge 46 of rail 41. This construction provides guidance for the lower edge of the door without the addition of friction from lateral guides. As the center of gravity of the door is esentially over the vertical centerline of the rollers, the lateral component of force against the top guide flange 30 is.

minimized.

To prevent upward displacement of the rollers 40 from rail 41, the lower edge of the door reinforcing member 15 is provided with an outwardly extending flange 47 which is spaced beneath the rail 41. In the event that the roller 40 may bounce upwardly as a result of impact when the sliding door engages end stops, the projecting flange 47 will prevent the rollers from jumping off the rail 41. The rail 41 is supported from the side wall of the car 1 by a series of U-shaped spacing members 48.

In accordance with the invention, an inflatable seal 49 is mounted within the confines of the door 3 and is adapted to automatically inflate on the closing of the door to provide a weather-tight seal between the door and the door frame on the car.

Seal 49 extends around all four sides of the door 3 and is mounted in a channel 50 which is secured to the edge members 12, 13, 14 and 15. The seal includes a generally rectangular base portion 51 which is connected by a pair of flexible side walls 52 to a head 53. The seal 49 is a snap-type, and in the deflated condition, the side walls 52 have a reverse bend so that the outer surface of the head 53 is located within the outer extremity of the folded side walls, as shown in FIGS. 2 and 3. By introducing hydraulic fluid into the interior 54 of the seal, the side walls 52 will snap outwardly to the extended condition where the head 53 will engage the door frame to provide a weather-tight seal between the door and the frame. The inner edges of the channel 50 are provided with beveled edges 55 which accommodate the expansion and retraction of the seal 49.

The seal 49 is adapted to be automatically inflated as a consequence of operation of the door locking mechanism. As shown in FIGS. 4 and 5, the door locking mechanism includes a latch 56 which is connected to the door and is adapted to engage a pin 57 mounted on the door frame to hold the door in the locked position. Pin 57 is provided with an enlarged head 58, while the inner end of the pin is mounted on a support 59 secured to the car I. The outer extremity of the latch arm 56 terminates in a hooked end 60 which is adapted to engage the pin 57 inwardly of the enlarged head 58.

The inner end of the latch arm 56 is curved, as indicated by 61, and is pivotally connected by pin 62 to a projecting ear 63 on locking lever 64. Locking lever 64 is mounted for rotation about a shaft 65 see FIGS. 4 and 6 which extends outwardly from a base plate 66 connected to the door plate 10 by bolts 67. With this construction, the lever arm 64 is adapted to be rotated through approximately 90 from a locking position, in which the lever arm extends vertically downwardly from the shaft 65 and the latch arm 56 is in the locked position, to an unlocked position in which the lever arm extends generally horizontally and the latch arm 56 is in the unlocked position.

The upper surface of the latching arm 56 is provided with a projection 68 which is adapted to engage a stop 69 on base plate 66 when the latch arm is in the unlocked position, thereby preventing the latch arm from dropping vertically by gravity to a vertical position. When the door is open, engagement of the projection 68 with stop 69 will insure that the hooked end 60 is located in substantial horizontal alignment with pin 57. Thus, if the door 3 accidentally slides to the closed position, the outer tapered end 70 and the arm 56 will rideover the pin 57 and the hooked end 60 will drop behind the pin, thereby automatically restraining the door from opening again until the latch arm 56 is pivoted upwardly.

The stop 69 provides an added function in that it prevents the latch arm 56 from swinging clockwise, as shown in FIG. 4, in the event the car is subjected to impact. In this situation, the upper surface of the latch arm will engage the stop 69 to prevent the latch arm from swinging clockwise to an inoperative position.

An additional stop 71 is mounted on the base plate 66 and limits the downward swinging movement of the lever 64 and positions the lever 64 for sealing as will be hereinafter described.

In accordance with the invention, movement of the locking lever 64 to the locked position automatically supplies hydraulic fluid to the seal 49 to inflate the same. In this regard, movement of the locking lever to the locked position actuates a diaphragm-type cylinder or pump 72 to supply hydraulic fluid to the inflatable seal 49 to inflate the same. As best illustrated in FIGS. 4 and 6, the cylinder 72 includes a dish-shaped base member 73 which rests against the door plate 10 and a dish-shaped cover 74 encloses the upper end of the base plate 73. Peripheral flanges of both the base 73 and cover 74 are secured to a mounting plate 75 by a series of bolts 76. The periphery of the plate 75 extends inwardly toward the door plate 10 and terminates in an outwardly extending flange 77 which is attached to the plate 10 by bolts 78. The diaphragm cylinder 72 also includes a flexible, rubber-like, annular diaphragm 79 having its outer margin secured between the flanges of the base 73 and cover 74. As shown in FIG. 6, the inner portion of the diaphragm 79 is secured between a ring 80 and a dish-shaped diaphragm plate 81 by a series of bolts 82.

The diaphragm 79 is normally urged outwardly in a direction toward the cover 74 by a coil spring 83 which is mounted between the inner surface of the diaphragm plate 81 and the base plate 73. Secured within a central opening in the diaphragm plate 81 is a shaft 84 and the outer end of the shaft is pivotally connected to the end of a lever 85 by pin 86. As best illustrated in FIGS. 4 and 6, the outer end of the lever 85 is provided with a slot 87 which receives the upstanding shaft 84 attached to the diaphragm plate 81. The cover 74 is provided with a recess or slot 88 which receives the outer end of the lever 85.

The lever 85 which is attached to the diaphragm plate 81 is mounted for rocking movement about a fulcrum or shaft 89 which is mounted between lugs 90 that extend upwardly from the plate 66. The inner end of the lever 85 is adapted to ride on an inclined surface 91 formed on a generally arcuate extension 92 of the locking lever 64. When the door is in the open position, the locking lever 64 will be in the phantom position shown in FIG. 4, extending generally horizontal and the end of the lever 85 will be in engagement with the low end of the inclined surface 91. In this condition, the lever 85 will be tilted as shown by the phantom lines in FIG. 6 and the diaphragm 79 will be in the outer position within the cylinder 72. As the locking lever 64 is rotated 90 to the locked position, which is the full line position in FIG. 4, the end of the lever 85 rides up the inclined surface 91, thereby pivoting the lever 85 to the horizontal or full line position, as shown in FIG. 6, and moving the plate 81 and diaphragm 79 toward the base 73 to thereby force the fluid from the fluid chamber 93 of the cylinder 72 to the seal 49 to inflate the same, as will be hereinafter described in greater detail.

As the locking lever 64 is moved to the unlocked position, shown by the phantom lines in FIG. 4, the end of the lever 85 will ride downwardly on the inclined surface 91, thereby pivoting the lever 85 about the fulcrum 89 and moving the diaphragm plate and diaphragm 79 toward the cover 74 to increase the volume of the chamber 93 and thereby draw fluid from the seal 49 back into the chamber 93. This acts to deflate the seal.

As shown in FIG. 12 in order to supply hydraulic fluid from the diaphragm cylinder 72 to the seal 49, the base 73 is provided with an embossment 94 which defines a recessed area 95 that communicates with the chamber 93. An opening 96 is formed in the base plate 73 and provides communication between the recessed area 95 and a passage 97 formed in a block 98 that is located between the door plate and the spacing plate 75. Passage 97 communicates with a passage 99 which in turn is connected to a second passage 100 in block 98. An O-n'ng 100a is located in a groove in block 98 so that a seal is effected by merely bolting the cylinder half 73 to the block. See FIG. 4. Fluid line or tube 101 is connected to the end of the passage 100, and line 101 leads to the inflatable seal 49 as will be more fully described.

In order to fill and drain the hydraulic system of fluid, the block 98 is provided with a passage 102 which communicates with passage 100 and a line 103 is connected to the end of the passage 102. Opposite end of the line 103 is connected to a passage 104 in a block 105 which is welded within an opening in the facing plate 75, as

best illustrated in FIG. 9. Passage 104 is connected to a passage 106 in block which in turn is connected to an outer passage 107. A plug 108 is normally threaded within the passage 107 to close off the opening. By removing the plug 108, hydraulic fluid can be introduced or withdrawn from the hydraulic system contained within the door 3.

The volume of the fluid chamber 93 in diaphragm cylinder 72, when the door is in the open position and the chamber is expanded is approximately equal to the volume of the chamber 54 of inflatable seal 49. When the locking lever 64 is moved to the closed position, the pumping lever 85 will be operated to force fluid from the chamber 93 to the inflatable seal 49 to fill the entire volume of the seal. As the inflating mechanism is adapted to be used with doors of various size which may have seals of varying volume, the diaphragm cylinder 72 is designed for the door with the seal of largest volume. When seals of smaller volume are employed, an expansion cylinder 109 is utilized to receive the excess fluid that is being discharged from the diaphram cylinder 72. As shown in FIG. 7, expansion cylinder 109 includes a dish-shaped base member 110, which is secured against the outer surface of the door plate 10, and a dish-shaped cover 111 encloses the outer end of the base 112. The peripheral edges of the base 110 and cover 111 are secured together and to the facing plate 75 by a series of bolts 112.

A flexible-rubber-like diaphragm 113 is located within the cylinder 109, and the peripheral margin of the diaphragm is connected between the flanges of the base 110 and cover 111, as shown in FIG. 7. The central portion of the diaphragm 113 is attached between a pair of plates 114 which are connected together by bolts 115.

To urge the diaphragm 113 inwardly toward the base 1 10, a coil spring 116 bears between the inner surface of the cover 111 and the outer plate 114. The interior portion of the cylinder 109, between the diaphragm 113 and the base 110 defines a fluid chamber 117 which is connected to the hydraulic system contained within the door. A second spring 1 16a is also contained within cylinder 109. The length of spring 116a is related to the volume of the fluid chamber 117 and is arranged so that only spring 116 bears against plate 114 so long as the displaced volume of chamber 117 is equal to the difference in volume of the largest and smallest inflatable seals 49 to be used in association with door 3. The action of the spring 116a will later be described in detail. To connect the chamber 117 to the hydraulic system, the base 1 10 is provided with an embossment 118 which defines a recessed area 119 that communicates with chamber 117. Passage 120 provides communication between the recess 119 and a vertical passage 121 formed in block 98, and passage 121 is connected to passage 100. As shown in FIG. 7, bolts 122 connect the flanges of cover 111 and base 110 to block 98.

The diaphragm cylinder 109 is designed so that the force of the spring 116 is less than the force required to expand the seal 49. Thus, when sufficient fluid has been delivered from the diaphragm cylinder 72 to fill the seal 49, any excess fluid will act against the diaphragm 113 and overcome the force of spring 116 to fill the chamber 117 before the seal will be pressurized and compressed against the door frame. Thus, the diaphragm cylinder 109 functions as a reservoir or expansion chamber for excess fluid delivered from the cylinder 72 to the inflatable seal 49.

In addition to the cylinders 72 and 109, a third diaphragm cylinder 123 is utilized to pressurize the fluid within the seal 49. The pressurizing cylinder 123 is also mounted within the confines of the door 3, and as shown in FIG. 8, includes a dish-shaped base member 124 which rests on the door plate 10, and the outer end of the base 124 is enclosed by a dish-shaped cover 125. The peripheral flanges of the base 124 and cover 125 are secured together by a series of bolts 126.

A flexible-rubber-like diaphragm 127, similar to diaphragm 79, is located within the cylinder 123, and the peripheral portion of the diaphragm is secured between the flanges of the base 124 and cover 125.

As shown in FIG. 8, a ring 128 is mounted on the inner surface of the central portion of the diaphram 127, while a plate 129 and ring 130 are mounted on the opposite side of the diaphragm and are connected to the ring 128 by a series of bolts 131.

The diaphragm 127 is connected to the inner end of a screw 132, and to provide this connection, the screw is formed with a neck portion 133 of reduced diameter which'is secured within an opening in the ring 130. As shown in FIG. 8, the screw 132 is threaded within an opening in nut 134 that is welded within an opening in the cover 125. By threading the screw 132 within the nut 134, the diaphragm 127 will be correspondingly moved within the cylinder 123.

To thread the screw 132 within the nut 134, a lever 135 is secured to the'outer end of the screw. When the door is in the open position the lever 135 will hang vertically as shown by the phantom lines in FIG. 4. After the locking lever 64 has been moved to the locked position to thereby supply hydraulic fluid to the inflatable seal 49, the lever 135 is rotated 270 in a counterclockwise direction as shown in FIG. 4, thereby threading the screw 132 inwardly and applying pressure to the hydraulic fluid located within the fluid chamber 136 which is connected through the hydraulic system through the seal 49. This acts to fully expand the seal 49 against the surfaces of the door frame to provide a weather-tight enclosure.

The total volume of cylinder 109 is approximately equal to the difference of volume of the largest and smallest seals to be used with different models or sizes of door 3 plus the volume of cylinder 123. When plate 114 is displaced beyond the first of these volumes, it encounters spring 116a whose pressure is equal to the final system pressure. Thus the operation of pressurizing cylinder 123 applies final pressure to the entire system regardless of seal size.

When the lever 135 is in the pressurizing position, as shown by the full lines in FIG. 4, the end of the lever is supported on a stop 136 formed on the end of the locking lever 64. To provide a seal against entrym the lever 135 is formed with an inwardly extending lug 138 which is located flatwise with respect to a lug 139 that extends outwardly from a plate 140 secured to the door face 10. As seen in FIG. 11, lugs 138 and 139 have registering holes 141 through which a padlock can be inserted to thereby lock the door opening mechanism against unauthorized entry.

The construction described provides an interlock between the locking lever 64 and the pressurizing lever 135 which insures that the locking lever must be actuated first when locking the door,and moreover, it insures that the pressurizing lever must initially be moved to the non-pressurizing position before the locking lever is moved to the unlocked position, thereby providing a built-in operating sequence both on locking and unlocking so that detailed instructions to the operator are unnecessary.

As shown in FIG. 13, to connect the fluid chamber 136 with the hydraulic system the base 124 of cylinder 123 is provided with an embossment 142 which defines a recessed area 143 that communicates with chamber 136. An opening provides a connection between the recessed area 143 and a passage 144 in block 145 that is secured between the door plate 10 and mounteding plate 146. Passage 144 is connected to passage 148. In addition, line 101 which communicates with passage 100 in block 98 is also connected to the passage 148. An O-ring 148a is located in a groove in block 145 so that a seal is effected merely by bolting bottom half 124 of cylinder 125 to the block.

Extended normally from horizontal passage 148 is a passage 149 which communicates with a passage 150 in block 151. As shown in FIG. 10, block 151 is secured to the outer surface of block 146 by a series of bolts 152, and to provide a seal between the blocks an O-ring 153. is mounted within a groove in the outer surface of block 146 and borders the passage 149. As shown in FIG. 10, the outer end of passage 150 is connected to passage 154 and a line or flexible tube 155 connects the horizontal passage 154 with the inflatable seal 49. The line 55 passes through a series of openings 156 formed in the lower door member 15, as shown in FIG. 2 and is connected to the portion of the seal 49 which extends along the lower margin of the door. It should be noted that the hydraulis lines 101 and 155 are not exposed, but are entirely confined within the door so that there is no danger of the lines being accidentally contacted by outside objects.

With the door 3 in the open position, the locking lever 64 is located horizontally as shown by the phantom lines in FIG. 4, and the pressurizing lever 135 is located vertically, also shown by the phantom lines in FIG. 4 As the door slides along the rail 41 to the closed position, latch arm 56 will be located at a slight angle to the horizontal, due to the engagement of the projection 68 with the stop 69. As the door approaches the closed position the forward edge 71) on latch arm 56 will ride on the pin 57, moving the latch arm 56 upwardly by a wedging action so that the hooked end 60 will drop behind the pin. The locking lever 64 is then rotated downwardly 90 to the vertical position, thereby pivoting the lever 85 and forcing hydraulic fluid from the chamber 93 through the lines 1111 and 155 to the seal 49. Any excess fluid over and above that required to fill the seal 49 will be supplied to the expansion chamber 117, due to the fact that the pressure of spring 116 acting on the diaphragm 113 in diaphragm cylinder 109 is less than the force required to fully pressurize the seal 49.

After the locking lever 64 has been moved to the locked or vertical position, shown by the full lines in FIG. 4, the pressurizing lever is rotated 270 to the horizontal position, thereby threading the screw 132 inwardly and pressurizing the fluid in chamber 136 and in the entire hydraulic system to thereby force the seal 49 into tight engagement with the door frame. With the locking lever 64 and the pressurizing lever 35 in the position shown in FIG. 4, a padlock can be inserted through the aligned holes 141 to secure to the mechanism in the locked position.

On opening the door, the padlock extending through holes 141 is initially removed and the pressurizing lever 135 is rotated clockwise 270 thereby threading the screw 132 outwardly and relieving the pressure on the fluid of the hydraulic system. Locking lever 64 is then moved to the horizontal position, moving tilting lever 85 to the phantom position shown in FIG. 6 and enlarging the volume of the chamber 93 to cause the fluid within the seal 49 to be withdrawn to the chamber 93. As had been noted, the volume of chamber 93, when in the expanded condition is slightly greater than the volume of the seal 49, so that substantially all of the fluid within the seal will be withdrawn to the chamber 93 when the door is in the unlocked position.

With the withdrawal of the fluid from the seal 49, the outer portion or head of the seal will snap back to its inner position, out of contact with the door frame. In this condition the seal is spaced approximately V4 inch from the door frame so that the door can then slide freely with respect to the side wall of the car. By use of the inflatable seal a larger clearance can be utilized between the door 3 and the side wall of the car 2 thereby insuring that there will be a minimum of frictional resistance to sliding movement of the door.

The mechanism for inflating and deflating of the seal is contained within the confines of the door, and is operated manually without the necessity of an outside power source. The hydraulic system is permanently sealed against leakage,and is economical to install and maintain since there are no finely machine cylinders, packings, etc., that are required in the system.

To aid in sliding movement of the door between the open and closed positions, V-grooved rollers are used in conjunction with anti-friction pads at the upper end of the door. This guide system provides self-guideance with a minimum of friction and also insures that the center of gravity of the door is directly over the center of the rollers so that lateral components of force against the anti-friction pads at the top of the door are minimized.

While the above description has illustrated the sliding flush door as utilized with a railway car, it is contemplated that the door can be used in other installations such as aircraft hangers, buildings, etc., and particularly those installations where an external power source is not available to inflate and deflate the sealing mechanism, as in shipping containers.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

l. A sliding door construction, comprising a wall having an opening therein, a sliding door disposed to enclose the opening and mounted for sliding movement along the wall between an open and a closed position, locking means for locking the door in the closed position, an inflatable seal secured to the inner surface of the door adjacent the wall and movable between an inflated condition, wherein the seal is disposed in contact with the wall bordering the opening to seal the joint between the wall and the door, and a deflated position in which the seal is disposed within the confines of the door out of contact with the wall, hydraulic fluid supply means carried by the door and including a fluid reservoir and a supply conduit connected to the seal, actuating means responsive to locking the door in the closed position for supplying fluid from said reservoir to the seal to inflate the same, pressure means carried by the door and operably connected to the seal, and operating means on the door and operably connected to said pressure means for pressurizing the fluid within the seal.

2. The door construction of claim 1, wherein said locking means includes a first locking member connected to the wall and a second locking member disposed on the door and engageable with said first locking member, said locking means also including an operating member connected to said second locking member and movable between a locked and an unlocked position, said operating means movable between a pressurizing position and a non-pressurizing position.

3. The door construction of claim 2, in which said operating member is disposed in engagement with the operating means when the operating means is in the pressurized position and the operating member is in the locked position, and said door construction includes 1 connecting means for connecting said operating member to said operating means.

4. The door construction of claim 2, including means for preventing movement of the operating member from the locked to the unlocked position when the operating means is in the pressurizing position.

5. A sliding door construction, comprising a wall having an opening therein, a sliding door disposed to enclose the opening and mounted for sliding movement along the wall between an open and a closed position, locking means for locking the door in the closed position, an inflatable seal secured to the inner surface of the door adjacent the wall and movable between an inflated condition, wherein the seal is disposed in contact with the wall bordering the opening to seal the joint between the wall and the door, and a deflated position in which the seal is disposed out of contact with the wall, a hydraulic system located within the door and including a conduit connected to the seal, first pumping means carried by the door and connected to the conduit, first operating means responsive to locking the door in the closed position for operating the first pumping means and supplying hydraulic fluid to the seal, second pumping means carried by the door and connected to the conduit, and second operating means located on the door and operably connected to said second pumping means for operating said second pumping means to pressurize the hydraulic fluid in said seal.

6. The door construction of claim 5, wherein said first pumping means includes a chamber to contain hydraulic fluid and a pressure member disposed within the chamber, said pressure member being operably connected to said locking means through said first operating means whereby operation of said locking means will operate said pressure member to thereby supply hydraulic fluid from the chamber to the seal.

7. The door construction of claim 6, wherein the volume of the chamber is substantially equal to the volume of the seal.

8. The door construction of claim 6, wherein the pressure member is a flexible diaphragm.

9. The door construction of claim 5, and including an expansion reservoir connected to said conduit.

10. The door construction of claim 9, wherein said reservoir includes an expandable wall movable between a retracted position in which the reservoir has a limited volume to an expanded position in which the reservoir has a substantial volume.

1 l. The door construction of claim 10, and including resilient means for biasing the expandable wall to the retracted position, the force of said resilient means being greater than the force required to expand the seal whereby the seal will be moved to the expanded condition prior to movement of said wall from the retracted to the expanded position.

12. The door construction of claim 6, wherein said locking means includes a first locking member disposed on the wall, a second locking member mounted on the door and engageable with the first locking member, and a lever pivotally connected to the door and operably connected to said second locking member whereby pivotal movement of said lever will move the second locking member between a locked and an unlocked position with respect to said first locking member, said first operating means including an operating member connecting said lever and the pressure member.

13. The door construction of claim 12, wherein said pressure member is a flexible diaphragm, and the operating member is fulcrummed on the door, one end of said operating memberbeing connected to said diaphragm and the opposite end of said operating member being connected to said lever.

14. The door construction of claim 13, wherein said lever includes an inclined surface and said opposite end of the operating member is disposed to ride on the inclined surface as the lever is pivoted to thereby tilt said operating member and operate said diaphragm.

15. A sliding door construction, comprising a wall having an opening therein, a sliding door disposed to enclose the opening and mounted for sliding movement along the wall between an open and a closed position, locking means for locking the door in the closed position, an inflatable seal secured to the inner surface of the door adjacent the wall and movable between an inflated condition, wherein the seal is disposed in contact with the wall bordering the opening to seal the joint between the wall and the door, and a deflated position in which the seal is disposed out of contact with the wall, a conduit disposed within the confines of the door and connected to the seal, a first diaphragm cylinder having a first fluid chamber to contain hydraulic fluid and connected to the conduit and having a first diaphragm member disposed in said first chamber, locking means for locking the door in the closed position and movable between a locked and unlocked position, said locking means including an operating lever pivotally connected to the door, first operating means interconnecting the first diaphragm member and the lever whereby movement of said lever to the locked position actuates said first diaphragm member to force fluid from said first chamber through said conduit to said seal, said first chamber having a volume substantially equal to the volume of the seal, a second diaphragm cylinder having a second fluid chamber to contain hydraulic fluid and connected to said conduit and having a second diaphragm member disposed within said second chamber, a second operating lever pivotally mounted on the door and movable between a pressurizing and nonpressurizing position, a second operating means operably connecting said second diaphragm member and said second lever whereby movement of said second lever from the non-pressurizing position to the pressurizing position actuates said second diaphragm member and pressurizes fluid within the seal, a third diaphragm cylinder having a third fluid chamber to contain hydraulic fluid and operably connected to said conduit and having a third diaphragm member disposed within said third chamber and movable between a retracted position in which said chamber has a limited volume to an expanded position wherein said third chamber has a substantially greater volume, and resilient means for biasing said third diaphragm member to the retracted position, the force of said resilient meansbeing greater than the force required to move the seal from the deflated to the inflated position whereby the third diaphragm member will be retained in the retracted position until the seal is fully expanded. 

1. A sliding door construction, comprising a wall having an opening therein, a sliding door disposed to enclose the opening and mounted for sliding movement along the wall between an open and a closed position, locking means for locking the door in the closed position, an inflatable seal secured to the inner surface of the door adjacent the wall and movable between an inflated condition, wherein the seal is disposed in contact with the wall bordering the opening to seal the joint between the wall and the door, and a deflated position in which the seal is disposed within the confines of the door out of contact with the wall, hydraulic fluid supply means carried by the door and including a fluid reservoir and a supply conduit connected to the seal, actuating means responsive to locking the door in the closed position for supplying fluid from said reservoir to the seal to inflate the same, pressure means carried by the door and operably connected to the seal, and operating means on the door and operably connected to said pressure means for pressurizing the fluid within the seal.
 2. The dooR construction of claim 1, wherein said locking means includes a first locking member connected to the wall and a second locking member disposed on the door and engageable with said first locking member, said locking means also including an operating member connected to said second locking member and movable between a locked and an unlocked position, said operating means movable between a pressurizing position and a non-pressurizing position.
 3. The door construction of claim 2, in which said operating member is disposed in engagement with the operating means when the operating means is in the pressurized position and the operating member is in the locked position, and said door construction includes connecting means for connecting said operating member to said operating means.
 4. The door construction of claim 2, including means for preventing movement of the operating member from the locked to the unlocked position when the operating means is in the pressurizing position.
 5. A sliding door construction, comprising a wall having an opening therein, a sliding door disposed to enclose the opening and mounted for sliding movement along the wall between an open and a closed position, locking means for locking the door in the closed position, an inflatable seal secured to the inner surface of the door adjacent the wall and movable between an inflated condition, wherein the seal is disposed in contact with the wall bordering the opening to seal the joint between the wall and the door, and a deflated position in which the seal is disposed out of contact with the wall, a hydraulic system located within the door and including a conduit connected to the seal, first pumping means carried by the door and connected to the conduit, first operating means responsive to locking the door in the closed position for operating the first pumping means and supplying hydraulic fluid to the seal, second pumping means carried by the door and connected to the conduit, and second operating means located on the door and operably connected to said second pumping means for operating said second pumping means to pressurize the hydraulic fluid in said seal.
 6. The door construction of claim 5, wherein said first pumping means includes a chamber to contain hydraulic fluid and a pressure member disposed within the chamber, said pressure member being operably connected to said locking means through said first operating means whereby operation of said locking means will operate said pressure member to thereby supply hydraulic fluid from the chamber to the seal.
 7. The door construction of claim 6, wherein the volume of the chamber is substantially equal to the volume of the seal.
 8. The door construction of claim 6, wherein the pressure member is a flexible diaphragm.
 9. The door construction of claim 5, and including an expansion reservoir connected to said conduit.
 10. The door construction of claim 9, wherein said reservoir includes an expandable wall movable between a retracted position in which the reservoir has a limited volume to an expanded position in which the reservoir has a substantial volume.
 11. The door construction of claim 10, and including resilient means for biasing the expandable wall to the retracted position, the force of said resilient means being greater than the force required to expand the seal whereby the seal will be moved to the expanded condition prior to movement of said wall from the retracted to the expanded position.
 12. The door construction of claim 6, wherein said locking means includes a first locking member disposed on the wall, a second locking member mounted on the door and engageable with the first locking member, and a lever pivotally connected to the door and operably connected to said second locking member whereby pivotal movement of said lever will move the second locking member between a locked and an unlocked position with respect to said first locking member, said first operating means including an operating member connecting said lEver and the pressure member.
 13. The door construction of claim 12, wherein said pressure member is a flexible diaphragm, and the operating member is fulcrummed on the door, one end of said operating member being connected to said diaphragm and the opposite end of said operating member being connected to said lever.
 14. The door construction of claim 13, wherein said lever includes an inclined surface and said opposite end of the operating member is disposed to ride on the inclined surface as the lever is pivoted to thereby tilt said operating member and operate said diaphragm.
 15. A sliding door construction, comprising a wall having an opening therein, a sliding door disposed to enclose the opening and mounted for sliding movement along the wall between an open and a closed position, locking means for locking the door in the closed position, an inflatable seal secured to the inner surface of the door adjacent the wall and movable between an inflated condition, wherein the seal is disposed in contact with the wall bordering the opening to seal the joint between the wall and the door, and a deflated position in which the seal is disposed out of contact with the wall, a conduit disposed within the confines of the door and connected to the seal, a first diaphragm cylinder having a first fluid chamber to contain hydraulic fluid and connected to the conduit and having a first diaphragm member disposed in said first chamber, locking means for locking the door in the closed position and movable between a locked and unlocked position, said locking means including an operating lever pivotally connected to the door, first operating means interconnecting the first diaphragm member and the lever whereby movement of said lever to the locked position actuates said first diaphragm member to force fluid from said first chamber through said conduit to said seal, said first chamber having a volume substantially equal to the volume of the seal, a second diaphragm cylinder having a second fluid chamber to contain hydraulic fluid and connected to said conduit and having a second diaphragm member disposed within said second chamber, a second operating lever pivotally mounted on the door and movable between a pressurizing and non-pressurizing position, a second operating means operably connecting said second diaphragm member and said second lever whereby movement of said second lever from the non-pressurizing position to the pressurizing position actuates said second diaphragm member and pressurizes fluid within the seal, a third diaphragm cylinder having a third fluid chamber to contain hydraulic fluid and operably connected to said conduit and having a third diaphragm member disposed within said third chamber and movable between a retracted position in which said chamber has a limited volume to an expanded position wherein said third chamber has a substantially greater volume, and resilient means for biasing said third diaphragm member to the retracted position, the force of said resilient means being greater than the force required to move the seal from the deflated to the inflated position whereby the third diaphragm member will be retained in the retracted position until the seal is fully expanded. 